Mechanism for feeding powdered material



Nov. 24, 1925- C. :,QNGaNCKER MECHANISM FOR mamma PQWDERED MATERIAL fl i5 Original Filed Sept.

vw fesses 1 Nov. 24, 1925- 1,563,295 C. LONGENECKER MEGHANISM FORl FEEDING -POWDERED MATERIAL 2 Sheets-Sheet 2 Original Filed Sept. 29. 1921 Patented Nov. 24, 1925.

UNITE!) i STATES (HARLES LONGENECKER, OF IPH'ADELPHIA, PENNSYLVANIA.

MECHANISM FOR FEEDING POWDERED MATERIAL.

Application filed September 29, 1921, Serial No. 504,130. Renewed April 5, 1924.

To all whom t muy conce/m.'

Be it known that I, CHARLES LoNGnNEeKnn, residing at Philadelphia, in the county of Philadelphia and State of Pennsylvania, a citizen of the United States, have invented or discovered certain new and useful lmproveinents in Mechanism for Feeding Powdered h'laterial, of which iniliirovements the following is specification.

ln the form or construction of apparatus in which the pulverized fuel is moved from the tank or other source of supply along a pipe or conduit provided with successive ports or openings through which the fuel drops or is drawn, the powdered fuel is moved by the conveying` screw so rapidly that a proper amount of fuel will not pass through the ports or openings into the.

branch pipes. The object of the invention described herein relative to certain improvements in this class of apparatus whereby the powdered fuel may be fed to the branch pipes in substantially equal and uniform quantities. i

In the accompanying drawings forming a part of this specification, Fig. 1 is a plan view showing a fuel supply hopper and means embodying the improvements claimed herein for moving the pulverized fuel from the hopper to the branch pipes leading to the burners; Fig. 2 is a `view partly in elevation and partly in section of the construction shown `in Fig. 1; Fig. 3 is a sectional elevation on a plane indicated by the line IIL-III, Fig. 2; Fig. l is a similar view, the plane of section being indicated by the line 11T-*117, Fig. 3; Figj is a sectional view on a plane indicated by the line V-V, Fig. 3, 'and Fig. 6 is a view similar to Fig. 5 illustrating a modification of the construction shown in Fig. 5.

ln'apparatus for feeding pulverized fuel from a hopper through a conduit from which the pulverized material passes to branch pipes, it is customary tol provide means for returning` all powdered fuel which has not been diverted into the branch pipes to the hopper. In some of these systems, the branch pipes are connected to the conduit through which material passes while being fed out from the hopper. In other systems the branch pipes are connected to what might be termed the return conduit. The former construction is shown and described in an application filed by me May 141;, 1920, Serial No. 381,498, and the latter system in another application filed by me August 5, 1920, Serial No. 401,310. As the latter form or construction is preferable in practical operation, the invention claimed herein is shown and described in connection with such form, but it will be understood that the broader claims are not limited to a construction in which the branches are sup,- plied from the return conduit.

As described in application Serial No. 401,310, above referred to, the pulverized fuel is forced from the hopper 1 through the conduit 2 by the screw conveyor 3 at the outer end of this conduit 2, the powdered fuel drops through a passage L1 from which it is forced by a conveyor 5` through the return conduit 0 having its opposite end connected to the tank or hopper 1 at or near the lower end thereof.

At suitable points along the conduit G, openings 7 are formed in the lower side of the conduit and into such openings project portions of shells 9 formed `of metal and having slots 10 therein, said slots extending, when the shell is in position, under the conduit transversely of the latter. v These shells are preferably screwed into tubular casings 11 `having saddles 12 fitting around the conduit. At one end, these casings are provided with chambers A connected to a source of fluid under pressure, and their opposite ends are adapted to be connected to pipes 18 for conveying the fuel` to the burners. lVithiu these casings are arranged cylindrical valves 9" 8 movable longitudinally in the shells to regulate the liow of powdered fuel through the slot 10 and adjustn'ient is effected by moans of threaded stems 111 secured to one end of the valves S and passing through rotatable nuts 15 mounted in the heads of the casings. On these nuts are secured operating pulleys 1G by the rotation of which the valves can be shifted back and forth in the shells 9. At their rear ends the valves are provided with ports 17 through which air` supplied to the chamber in the casing by the pipes 18 will flow through the valves and into the branch pipes 13. It will he observed that n by the longitudinal movement of these 10 valves, not only-will the How of powdered fuel into the pipes 13 be controlled but also the flow of air through the valves and the pipe 13. It is preferred to so construct the valves that the ports 17 will be opened to 110 allow the flow of air through the branches 13 before any portions of thc slots 10 in the vpipe or conduit '6.

shells 9 areopened to permit of the flow of powdered fuel into the branch pipes.

By reference to Figs. 2, 4f, 5 and 6, it will be observed that the spi 'al blade forming a part of the conveyor 5 is not continuous but is made in sections 19t-between which there is a substantial gap. The sectional conveyor is arranged in the conduit/(iso that the blade sections 19 are intermediate adjacent openingszin the conduit in whichlthe shells 9are located and are made shorter than the distance between adjacent slots. It results from thisconstruction that the only movement ofthe powdered fuel across vthe slots l() will be due to the push of the section of the screw inadvance of such slots and that the lfuel i-sfnot swept across the slots while in contact with the blades and that the section of the screw in the rear of the slots will onl-ytake awayas much of the fuel asmay be vforced toit by the feed ot the priorsection. .In other words,` b v thus making `the screw sectionsithere will be a certain delay in themovement ofthe fuel above and adjacent to the location of the slots l0, thus all'ording thetime for the llow of the fuel through such slots into the branches.

In order to insure the entrance of the powdered fuel into these slots, the `wall of the shell in advanceof the slot is cut away as indicated at nl, Fig. 5. The surface of this cutaway portion will, lwhen the parts of the mechanism are adjusted together, be substantially 'flush with the 4bottom of the Theopposite side of the slot-will form an abutment Z) which will tend to `check the 4movement of the fuel sliding nl oiigtlie bottomlof-theconduit and direct the powdered fuel ydown through the slot.

4Tn Vlieu of the construction shown in Fig. 5

an ordinary -slotzmayibe formed'in the shell and the latter may beso adjusted that one wall o'l said slot asc will be in a plane of the bottom of the conduit, as shown in lt is characteristic of both of these constructions that ithe transverse area ol' the Ascrew Ain front of the slots be forced down through the latter.

Itis also characteristic of fthe improvement described herein that the powdered vmaterial will, `while passing along the portions of the conduit in which 'the slots are located, move parallel with the axis'of the conduit or at right angles to the slot, Ywhereas in former constructions wherein the blade ot the conveyor was continuous, the material moved angularly across the slots.

l claim herein as my invention:

1. rlhe combination of an 'unobstructed conduit having .a plurality of openings in spaced relation in itslower side and a rotating screw for moving `the :material along the conduit, the blade of the screw being` formed in sections located intermediate adjacent openings and adapted to move forward material which will be passed beyond a preceding port.

2. The combination of a conduit having a pluralityof openings in spaced relation in its lower side, rotatable shells arranged at an angle to the axis of the conduit and so arranged in the openings that portions of the shells will extend into the conduit, the portions of -the shells 'extending into the conduit beingslotted, and a rotatable screw vfor moving the powdered material alongvthe conduit, the blade of the screw being formed in sections locatedintermediate adjacentshells.

3. Thecombination of a conduit having a plurality ot openings in spaced relation in its underside, shells arranged at an. angle Vto the axis of the conduit: and having portions extending into the conduit, the portions e.\'temlinjf into the conduit 'being slotted, a rotatable screw for moving powdered fuel along` the conduit, the blade of fthe screw 'being formed in sections 'located intermediate'adjacent shells, and valves for regulating the flow of powdered lfuel intothe shells.

4f.. The combination of a conduit having a plurality of openings'in s paccdrelation in its underside, shells-arranged atan angle to the axis ofthe conduit, and having` portions extending through -said openings into `the conduit, such Vportionsl vhaving slots, -fvalves controlling the tlow of powdered `material and air intosaid shells, means forshifling said Valves, and a yrotalal'ile screw j'for unoring powdered material along the conduit, the bladeof the screw being formed in secvtionslocated intermediate adjacent shells.

5. The combination-cfa conduit, a..plnral ity of `slots in spaced relation transverse of the conduit,.abutments yinthe conduit 'inthe rearlof the slots, and a lrotatable screw for moving material through the conduit, the blade of the screw being formed in sections located intermediate adjacent slots.

In testimony whereof I have hereunto set my hand.

CHAR-LES BQNGENECKER.

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